Management of Deformities Secondary to Bone Dysplasia

MANAGEMENT OF DEFORMITIES SECONDARY TO BONE DYSPLASIA

Stuart L. Weinstein, M.D. Professor Department of Orthopaedic Surgery University of Iowa Iowa City, Iowa 52242 In evaluating a patient with skeletal dysplasia the ortho- atlas. The spine shows characteristic decrease in the inter- paedic surgeon must keep several general concepts in pedicular distances on the AP view proceeding cephalad mind. Children with a skeletal dysplasia have dispropor- to caudal. On the lateral view, the pedicles are broad and tionate growth of various portions of the skeleton. These thick. The vertebrae are often bullet shaped. The AP disproportions may change during growth, i.g. in spon- diameter of the body is small with scalloping of the pos- dyloepiphyseal dysplasia congenita the trunk grows at a terior body margins (secondary to dural compression). relatively slower rate than the limbs during the first decade23. The pelvis has short square ilia, the sciatic notches are The portion of the skeleton primarily affected tends to narrow and deep and the acetabulum is horizontal. The have the greatest number of problems. Thus short trunked long bones are short and broad with wide flaring of the dwarfs tend to have more problems with spinal deformity metaphyses. The growth plate is like an inverted V and and atlantoaxial instability while short limbed dwarfs tend the fibula is longer than the tibia. The radial head may be to have more problems with joint malalignment, joint con- dislocated. tractures, etc. The more severely involved the individual Most achondroplasts will develop a thoracolumbar is, the greater the likelihood of having associated prob- kyphosis in the T10 to L4 region (Fig. 1). These curves lems. In addition, once the patient becomes ambulatory have been reported to reach 70 degrees23 40. These curves secondary deformities may be superimposed as the effects are usually supple and 90 percent will regress when inde- of weight bearing are exerted on the dysplastic bones and pendent gait is achieved23. However, some achondroplasts joints. will have anterior vertebral body wedging or body reces- It would be a monumental task to discuss the manage- sion leading to kyphosis. These kyphotic curves may prog- ment of all of the musculoskeletal dysplasias. Therefore ress and lead to anterior spinal cord compression requiring we will attempt to discuss the management of the mus- anterior decompression in addition to anterior and poste- culoskeletal problems of the most common skeletal rior fusion. If the deformity is less than 60 degrees and if dysplasias23. The basic principles used in the management the patient has no neurologic deficit, the kyphosis should of these conditions can then be applied to other skeletal be treated with a Milwaukee brace with kyphosis pads. dysplasias. Should the deformity reach greater than 60 degrees, consideration should be given to anterior and posterior spine Achondroplasia fusion5"4'23 Achondroplasia is the most common form of dwarfism2 16,20,23,34,36,40,43 and is the prototype of the short limbed dwarf. It is an autosomal dominant disorder but 80 percent of the cases represent spontaneous mutations40. These children are easily recognizable at birth. Their characteristic features include an enlarged head with frontal bossing, mild hypoplasia of the mid face, prominent man- dible, broad short hands with a space between the third and fourth digits (trident hand), rhizomelic shortening of the extremities with ligamentous laxity and slight hypotonia23'40. These patients commonly have delays in reaching milestones secondary to their disporportionate enlarged head and trunk relative to their extremities and relative hypotonia. Roentgenographic features of the cranium include over- all cranial enlargement with shortening of the base of the Fig. 1 skull while the foramen magnum is small and the frontal Achondroplasia. (A) Newborn with thoracolumbar kyphosis. (B) area is prominent. There may be occipitalization of the By age twenty-three months the kyphosis is resolving.

46 The Iowa Orthopaedic Journal Management of Deformities Secondary to Bone Dysplasia

Scoliosis is uncommon in achondroplasts and if present is usually insignificant5'23. Odontoid hypoplasia is also not a problem in these patients. Genu varum is a common problem in achondroplasia23. Ponseti feels that the genu varum is secondary to fibular overgrowth36. The bowing primarily affects the proximal leg but occasionally may be evident distally. Patients may complain of pain where the fibula comes in contact with the calcaneus if there is heel valgus to accommodate the genu varum. If the deformity is distal, this should be Fig. 3 treated by a supramalleolar osteotomy. Ligamentous laxity Achondroplasia. CAT scan of a twenty-three year old with contributes to the deformity although this tends to decrease symptoms of spinal stenosis. Note the narrowed canal in both with age. Bracing will not correct this deformity and is not AP and transverse planes. recommnended. These patients' extremities are extremely difficult to fit with an orthosis and the closeness of the Lumbar myelography may be difficult to perform and joints make them cumbersome. In addition, the brace acts even hazardous because of the small canal. Typically it will through lax ligaments rather than bone4'23. We have treated show pooling of dye at the body levels and filling defects the genu varum deformity by proximal fibular epiphyseo- at the disc levels and possibly a block at L3. desis in the preadolescent patients with mild deformity. In The treatment is adequate laminectomy. This usually older children with knee discomfort, resection of the encompasses five to ten levels and may require partial prominent fibular head and, in the more severe deformi- pediculectomy, facetectomy and formaninotomy. An inad- ties, opening wedge spike osteotomies have been done to equate decompression will often lead to increasing symp- correct the malalignment (Fig. 2)36. The deformities tend toms necessitating extension of the laminectomy in length not to recur. Flexion contractures are present about the and width. The facet joints are very close to midline in hip and elbow and are usually well tolerated. achondroplasts and thus postlaminectomy instability is usually not a problem. Therefore fusion is usually only needed if the facet joint congruity is disrupted5'23'28.

Pseudoachondroplasia Dysplasia Pseudoachondroplasia dysplasia was first described by Maroteaux and Lamy in 195929. Subsequently four forms have been delineated5'17 with both autosomal dominant and recessive inheritance and varying severity of musculoskeletal problems. It represents the second most common type of short limbed dwarf after achondroplasia. The disorder can be differentiated from achondroplasia because Fig. 2 the patients have a normal sized and shaped head, a greater Achondroplasia. Left, preoperative roentgenogram demonstrat- degree of ligamentous laxity, particularly about the wrists, ing genu varum and fibular overgrowth. Center, roentgenogram immediate postoperative opening wedge spike osteotomies and ankles, and knees, and severe lower extremity deformities proximal fibular head resections. Right, roentgenogram one year (Fig. 4). The disorder is not detectable at birth, the rhi- postoperatively. zomelic shortening becoming evident at age two to three. The most significant problem facing the achondroplast They have a waddling gait and excessive lumbar lordosis. is spinal stenosis. Approxinately 40 percent of adult patients Roentgenographically there is generalized involvement are affected; however, the number is significantly greater of both the epiphyses and metaphyses of the tubular bones. if one takes into account those with mnild symptoms5. The The epiphyses are delayed in their appearance and are etiology is the narrowed canal in the frontal and sagittal small and fragmented when they do appear8. The central planes (Fig. 3). Other contributing factors may include portions appear normal but the periphery is markedly increasing lumbar lordosis, herniated nucleus pulposis, deformed, especially at the sites of ligament insertions9. bulging annulae, hypertrophied facet joints and The metaphyses are splayed and frayed. The vertebrae osteophytes"15'23'28. The average age of symptom onset is show varying degrees of platyspondylia, being biconvex thirty-eight years' 28. The patients may present with either with anterior tonguing. The severity of these changes signs or symptoms of nerve root compression, cauda equina decreases with age. The pelvis demonstrates large ilia and syndrome, paralysis or claudication28. short ischia and pubi.

Volume 8 47 S. L. Weinstein

cation of the epiphyses may require the surgeon to use arthrography at surgery to insure proper joint alignment. These deformities have a tendency to recur; therefore slight overcorrection with the opening wedge osteotomies should be obtained at surgery to prevent recurrence (Fig. 5)2. Patients with pseudoachondroplasia dysplasia have a tendency to develop degenerative joint disease2'9'43 which may require joint replacements.

Fig. 5 Pseudoachondroplasia Dysplasia. Left, preoperative roentgenogram demonstrating genu varum. Note also the splaying and fraying of the metaphyseal regions. Right, roentgenogram one year postoperative bilateral opening wedge tibial and fibular osteotomies.

Scoliosis may develop but it is usually not severe and if progressive should be treated by standard Milwaukee brace Fig. 4 causes Pseudoachondroplasia Dysplasia. Seven year old male. Note therapy. Correction of the infra pelvic of pelvic the rhizomelic shortening and genu varum. The head and face obliquity is also helpful. If progression continues, surgical are normal. stabilization by standard techniques is recommended5. Hypoplasia of the odontoid is the most common dyspla- Over 80 percent of these patients develop malalignment sia of the odontoid seen in patients with pseudoachodnro- deformities of their lower limbs23. The most frequent pic- plasia if they have significant spine involvement. The tip ture is that of the windswept deformity with hip adduction of the odontoid is cone shaped and does not extend cephalad and knee valgus on one side and hip abduction and knee to the ring of Cl. Mild atlantoaxial instability may occur varus on the other23. This may lead to hip subluxation and in these patients and it is uncommon for them to develop pelvic obliquity. Patients may also have bilateral genu varum cervical myelopathy, however, it has been reported23. and fibular overgrowth or bilateral genu valgum. Genu recurvatum may also accompany these deformities. Brac- ing treatment is ineffectual for the same reasons men- Metaphyseal Chondrodysplasia tioned in achondroplasts. Wrist instability caused by ulnar Metaphyseal chondrodysplasia refers to a group of dis- deviation secondary to bowing of the radius and ulna in orders of defective enchondral ossification with major combination with ligamentous laxity may be a functional roentgenographic manifestations in the metaphyseal problem that can be managed by splints. region26. This disorder encompasses the disorders for- Surgical correction of the deformity is aimed at cor- merly referred to as metaphyseal dysostosis of the Jansen recting AP and sagittal plane deformity so as to achieve a (autosomal dominant)'9 or Schmid type (autosomal domi- level pelvis with the ankle and knee joints parallel to the nant)1',39, McKusick type- Cartilage-hair hypoplasia ground. At surgery, one must take into account the extreme (autosomal recessive)31, and metaphyseal chondrodyspla- degree of ligamentous laxity that contributes to the sia with pancreatic insufficiency and neutropenia (autoso- deformity. In addition, the delayed and incomplete ossifi- mal recessive)6'8"13'45. These disorders all have a common

48 The Iowa Orthopaedic Journal Management of Deformities Secondary to Bone Dysplasia bowing of the long bones with the lower extremities being physis is widened and irregular'0. All long and tubular affected to a greater extent than the upper extremities. bones are affected with the most severe changes occurring The bowing is slowly progressive and will lead to malalign- at the most rapidly growing bones. Normal bone curva- ment in over 50 percent of the cases23. Cooper, et al., tures are accentuated. The Jansen type may show more reported dilated cisternae of chondrocyte endoplasmic extreme changes with abnormal zones of ossification reticulum filled with a granular precipitate. They hypoth- extending down into the diaphysis. The skull may show esized that this represented a defect in enzyme transport evidence of increased sclerosis with prominent supraor- mechanism inhibiting intracellular transport of protein bital ridges and small paranasal sinuses'0. These patients, polysaccharide or a similar material from the rough endo- particularly the McKusick type, may also have problems plasmic reticulum to the golgi apparatus'°. with varus foot deformity secondary to distal fibular Metaphyseal chondrodysplasia of the Schmid type is the overgrowth. most common. These children are normal appearing at Coxa vara represents the most common problems in birth. In the toddler years, short stature becomes evident these disorders. When the neck shaft angle is less than as does bowing of the legs, a waddling gait and excess 100 degrees surgical correction by intertrochanteric val- lumbar lordosis. The head size is normal as are all blood gus osteotomy is indicated (Fig. 7). Postoperatively this chemistries. Metaphyseal chondroplasia of the Jansen type deformity tends not to recur and patients walk with less is evident in infancy. The head may be slightly enlarged. effort and report increased work tolerance2'23. In these dysplasias, roentgenographic changes are con- Genu varum is another problem in many of these patients. fined to metaphysis and growth plate regions (Fig. 6). The Bailey reports some success in treatment of genu varum metaphysis is widened, irregular and stippled, while the with a Blount brace2. This has not been our experience.

Fig. 7 Metaphyseal Chondrodysplasia. Top, preoperative roentgeno- Fig. 6 grams of a four year old female with Schmid type metaphyseal Metaphyseal Chondrodysplasia. Four year old with Schmid type chondroplasia demonstrating severe coxa vara. Bottom, same metaphyseal chondrodysplasia. Coxa vara is present. The physes patient two years after bilateral valgus intertrochanteric are widened and irregular. osteotomies.

Volume 8 49 S. L. Weinstein

When the genu varum is significant enough to cause mal- of this disorder is fairly high with Bailey reporting eight alignment of the knee and ankle joints or cause pain, it deaths in ten affected children in three families2. Roent- should be corrected with the appropriate osteotomy. Sco- genographically there is involvement of virtually all artic- liosis and odontoid dysplasia are not usual but have been ular and epiphyseal cartilage. The metaphyses are flared reported in metaphyseal chondrodysplasia2'5. and the epiphyses are late appearing and flattened. In a variant of this disorder, spondylometaphyseal chon- The clubfoot deformity is difficult to treat. Serial casting drodysplasia (autosomal dominant), the proximal femoral should begin soon after birth. Once the maximum benefits metaphysis is severely affected and the spine shows evi- of casting have been achieved, any residual deformity should dence of platyspondylia with anterior beaking25'26. These be corrected by soft tissue surgery and prolonged casting. patients may develop scoliosis and thoracolumbar junction The equinus component is difficult to correct and maintain, kyphyosis5'26. Kyphosis at the thoracolumbar junction should particularly in those patients with hip and knee contrac- be managed in the Milaukee brace with kyphosis pads. tures and probably fail unless the hip and knee problems Progression in the brace requires surgical fusion to pre- are corrected. If a recurrence occurs, or if the patient is vent the neurologic sequalae of progressive kyphosis. If first seen in the toddler years, it may be best to observe the kyphosis is greater than 60 degrees staged anterior the patient and accommodate the deformities in appropri- and posterior fusion is recommended5. Progressive sco- ate shoes. This is in light of the fact that some patients liosis should be managed in a Milwaukee brace regardless may function adequately despite incomplete correction. of age. However, when progression exceeds 45 to 50 When the patient is into the second decade and is ham- degrees, surgical stabilization is recommended5. pered by foot deformity, bony surgery such as triple arthrodesis, foot narrowing procedures, and supramalleo- Diastrophic Dwarfism lar osteotomies may be considered2. Diastrophic dwarfism is an autosomal recessive disorder Progressive hip dysplasia is seen in 80 percent of the described in 1961 by Lamy and Maroteaux27. The word patients'8. The hips are generally normal at birth, but may diastrophism is derived from the Greek word for twisted progressively subluxate and even dislocate. The acetabu- or tortuous. The patients with this disorder are recogniz- lar roof is slanted laterally (Fig. 8). Kopits has demon- able at birth by an abducted hypermobile proximally placed strated the femoral head to be flattened and bilobulated thumb (hitchiker's thumb). Other deformities include short and the femoral neck to be short23. The patients may broad hands with ankylosis of the PIP joints, clinodactyly develop symptoms of degenerative joint disease prior to of the little finger, absence of flexion creases, shortness the full ossification of the femoral head. Valgus intertro- of stature with micromelia (proximal segments affected chanteric osteotomies alone or in combination with an ace- most) and severe bilateral clubfoot deformities18"13'46. During tabuloplasty-may prevent or delay degenerative joint the neonatal period these patients have acute swelling in disease23. Once the joint develops degenerative changes the pinnae of the ear which eventually go on to calcification total hip replacement is the only alternative. Total joint or ossification. replacement in these patients may require the use of spe- The patients develop multiple complex problems with cially designed femoral components as well as acetabular joint contractures, subluxation and dislocations, degener- augmentation procedures sirnilar to those techniques used ative joint disease and spinal deformity. The mortality rate in joint replacements for congenital hip dysplasia.

Fig. 8 Distrophic Dwarfism. Natural history of hip dysplasia in a single patient is demonstrated from roentgenograms in infancy and early childhood on the left through the development of degenerative joint disease by age twenty-eight years in the far right. Note the stunting of lateral acetabular growth.

50 The Iowa Orthopaedic Journal Management of Deformities Secondary to Bone Dysplasia

The joint contractures (hip, knee, and elbow flexion side of the IP joint. Rotational osteotomy of the proximal contractures), may be very severe. They are secondary phalanx may be of some benefit23. to cartilaginous joint deformity as well as soft tissue contracture. Knee flexion deformity is probably secondary to Morquio's Syndrome the hip deformity and is accompanied by misshappened joint surfaces23. Release of soft tissue contractures about Morquio's Syndrome (mucopolysaccharidoses IV) is an the hip is associated with recurrence and increased joint autosomal recessive disorder that was the prototype of stiffness2. Should correction be indicated, extension the short trunk dwarf. It was described in 1929 by Mor- osteotomy may offer the best solution. quio and Brailsford7'3 and is the most common of the Spinal deformity developed in over 80 percent of the mucopolysaccharidoses. In addition to musculoskeletal patients'8. In one-half of the patients this may be limited abnormalities these patients may have aortic insufficiency, to excessive lumbar lordosis, which may be a compensa- corneal opacities and keratosulfaturia2 30'35'37'48. Older tory mechanism adjusting for hip flexion deformity2'4'47. patients may not secrete keratan sulfate in the urine and The onset of scoliosis occurs during the first five years McKusick has described a nonkeratan sulfate excreting of life4'5"17"18. These curves are progressive, become rigid variety32. The patients often have a broad maxilla, widely rapidly and will reach considerable magnitudes causing car- spaced teeth, cuspids slightly more prominent than usual diopulmonary compromise if left untreated4 5"17. The dou- and a thin enamal cap2l"37. All cartilage is involved with the ble curve pattern is most common. In early childhood the disorder. Ligament, tendon and capsular insertion sites curves are small and flexible and should be managed by a seem to be particularly involved with delayed and faulty Milwaukee brace to arrest or at least limit progression. If ossification30 3537. The disorder is not diagnosed at birth progression occurs despite bracing, early posterior fusion (fetal cartilage has no keratan sulfate) but skeletal lesions is indicated. Delaying the procedure only serves to increase may be seen by eight months of age37. the magnitude and rigidity of the curve4,5,17. For some By two years of age short stature and a waddling gait young patients with progression a Moe subcutaneous rod- become apparent. Pectus carinatum develops secondary to disproportionate growth between the spine and the ding and bracing without fusion may be an alternative'. Cervical kyphosis may be a significant problem in patients sternum23. The patients quickly develop hip flexion con- with diastrophic dwarfism and is not reported in other tractures, tightness in the tensor fascia latae and genu forms of dwarfism4'5"72346. In its extreme form it may valgum. With age these deformities and resultant disabil- lead to quadriplegia and death5. It is usually associated ities increase. with hypoplastic cervical vertebrae. Three-fourths of the The bases of the metacarpals are conically shaped and cases of cervical kyphosis will resolve without treatment4 5. carpal bone ossification is retarded. The ulna is shorter than the radius with its distal end If the deformity is progressive, threatening neural func- being radially inclined. tion, surgical intervention is indicated. Since the The ulnar side of the distal radial metaphysis has a partic- majority ularly jagged appearance. Ligamentous laxity about the of these patients have cervical spina bifida occulta, pos- wrist dorsal-volar terior fusion alone difficult and consideration may allow displacement and distraction may prove of up to 2.5 cm'. This combination leads to decrease grip should be given to anterior strut grafting4'5"17. and pinch strength and disability. Wrist stabilization by In the lumbar spine the pedicles are shortened, partic- fusion would seem the logical choice, however, attempts ularly in the lower levels as in achondroplasia. The inter- at fusion have been unsuccessful23. Thus, wrist splints pedicular distance may or may not be decreased4'47. These offer the best alternative. patients may develop symptoms of spinal stenosis in their The pelvis in Morquio's Syndrome is usually narrow. fourth and fifth decades and should they develop, The acetabular roof has a defect in ossification of the lateral decompression via laminectomy is the treatment of choice23. margin (Fig. 9). The femoral heads are small, unevenly Genu valgum, flexion contracture and dislocating patel- ossified in young patients and gradually become flattened lae are problems that occur about the knee in diastrophic and fragmented. The hips may go on to subluxate or dis- dwarfs and may contribute to the loss of ambulation in the locate but usually remain asymptomatic and require no second decade24. These may require soft tissue release treatment23. The greater trochanters are poorly ossified of contracture and/or osteotomy and extensor mechanism and all patients have some degree of coxa valga37. realignment. Genu valgum may reach disabling proportions in patients The hand deformities rarely require treatment. Inter- with Morquio's Syndrome by eight to ten years of age. phalangeal joint spaces usually synostose with time. The The proximal lateral tibial epiphysis growth is stunted (Fig. shortened, ovoid or triangular first metacarpal contribut- 10). This in combination with severe ligamentous laxity, ing to the "hitchiker" deformity may cause some difficulty contracted tensor fascia lata and iliotibial band leads to with pinch, but can be compensated for by using the ulnar increasing deformity. In time fragmentation may occur in

Volume 8 51 S. L. Weinstein

Fig. 10 Morquio's Syndrome. Fourteen year old male with Morquio's Syndrome and severe genu valgum with stunting of the growth of the lateral portion of the proximal tibial epiphyses.

The spine in Morquio's Syndrome is severely affected with platyspondyly consistently present. In young patients the vertebral height is greater centrally than peripherally. On the lateral view, the typical flame-shaped contours are seen with failure of ossification of the anterior superior and inferior vertebral margins37. Some vertebrae are snaller than adjacent vertebrae and are recessed usually at the thoracolumbar junction, thus narrowing the spinal canal. Scoliosis and kyphosis may ensue, but only to a mild degree23. In the thorax, the sagittal diameter is increased due to horizontal ribs and its mobility is severely restricted21'23. In the late second decade the spine will become rigid. The most significant problem in Morquio's Syndrome and the one most often recognized late is cervical myelopathy secondary to atlantoaxial instability. The instability is secondary to odontoid hypoplasia or aplasia and ligamentous laxity. More than 70 percent of patients with odontoid dysplasia have C1-C2 instability and 50 percent Fig. 9 of these will develop cervical myelopathy2"14'23. Morquio's Syndrome. Roentgenogram of the pelvis in a patient with Morquio's Syndrome. Upper, roentgenogram age five. Mid- Symptoms of myelopathy are usually present between dle, roentgenogram age ten. Lower, roentgenogram age four- the ages of six and ten years14'23. The first signs are teen. Note the narrow pelvis, the small unevenly ossified femoral usually decreased physical endurance despite a normal heads that become flattened and fragmented. The greater trochanters are poorly ossified. neurologic exam. These symptoms are often erroneously attributed to the lower limb deformities. Patients begin to do more sedentary activities. Gradually pyramidal tract the lateral femoral condyle as well as the proximal lateral signs develop (hyperactive reflexes, clonus, positive tibial plateau. Releasing the tensor fascia lata contracture Babinski, spasticity) generally involving one side of the early to prevent the deformity has been tried without body with the lower limbs primarily affected'423. The success37. Kopits reports good results without recurrence patients may complain of paresthesias in the legs but sen- using realignment osteotomies performed at eight to ten sation to pain and touch remains intact. Vibratory sensa- years of age. The reason for lack of recurrence is that the tion decreases as the myelopathy progresses. The pectus patient usually stops growing about this time23. Correction carinatum may protect the patient from hyperflexion but may also take into account the extreme degree of liga- sudden death has been reported23. The etiology of the mentous laxity present. myelopathy is cord compression and lateral displacement

52 The Iowa Orthopaedic Journal Management of Deformities Secondary to Bone Dysplasia

(accounting for the unilateral symptoms in 90 percent of lumbar lordosis23. At the thoracolumbar junction the ver- the patients) by a hypertrophic mass composed of poste- tebrae may be stunted anteriorly leading to kyphosis. rior longitudinal and transverse ligaments'4'22 23. These Coxa vara usually develops leading to a waddling gait ligaments hypertrophy as a result of abnormal motion and and if left untreated may lead to hip subluxation. To avoid produce a large mass of tissue situated posterior to the these complications, as well as, degenerative joint disease dysplastic odontoid. a valgus intertrochanteric osteotomy is recommended. A All patients with Morquio's Syndrome (as well as all psoas lengthening at the time of surgery may help to those with skeletal dysplasia) should have upright lateral improve the patient's lumbar lordosis. flexion extension cervical spine films to evaluate instability. Scoliosis and kyphosis may occur in patients with spon- The presence of odontoid aplasia or hypoplasia does not dyloepiphyseal dysplasia congenita. These deformities necessarily indicate atlantoaxial instability. When myelo- should be treated with standard Milwaukee bracing tech- pathy is suspected it can be further evaluated by magnetic niques. Should the curve be progressive despite nonoper- resonance imaging, metrizamide myelography with poly- ative methods, surgical stabilization is indicated. tomography or CT scan. The instability is reduced by halo Aplasia of the odontoid is another common finding in traction and the reduction maintained by posterior fusion. SED congenita (Fig. 11). One-third of the patients will If there is no mobility at the occiput C1 junction, the develop cord compression. Cervical myelopathy is evident occiput may be included in the fusion. Postoperatively the earlier in children with SED congenita than in those with patients are maintained in a halo cast or jacket until the Morquio's Syndrome. Symptoms may be evident in the fusion is solid, usually three to four months. Atlantoaxial newborn or neontal period. Cases of respiratory arrest instability with myelopathy should be treated prior to any with head flexion in the newborn period as well as quad- extremity realignment procedures, because of the dangers riplegia secondary to minimal head trauma have been of anesthetic intubation. Failure to treat this problem sec- reported23. Cervical myelopathy secondary to atlantoaxial ondary to lack of recognition may account for the inability instability should be suspected in any child with SED con- of patients to regain ambulation after lower extremity genita who is late in reaching psychomotor landmarks. realignment procedures14,22 Treatment consists of reduction with halo traction, posterior fusion and stabilization. Spondyloepiphyseal Dysplasia Congenita The management of skeletal deformities in patients with skeletal dysplasia is very demanding. The goals of treat- Spondyloepiphyseal dysplasia (SED) congenita is an ment must be individualized for each patient. Awareness autosomal dominant disorder in which the patient presents of the problems associated with skeletal dysplasias allows as a short trunked dwarf without visceral features (as the orthopaedic surgeon to identify these problems early distinguished from Morquio's Syndrome)41'42'44. The diag- and institute prompt treatment and hopefully to ultimately nosis is possible, although difficult at birth, for initially the alter the natural history of these problems and improve limbs are disproportionately short. However, in the pre- the patient's quality of life. school years the growth of the trunk lags behind the extremities. These patients may have mild frontal bossing, a long flat face with wide set eyes, normal sized hands and feet, pectus carinatum, and occasionally clubfeet2343. They may exhibit hyptonia and walking may be delayed. On standing, patients with spondyloepiphyseal dysplasia congenita exhibit an excessive lumbar lordosis and a pro- tuberant abdomen. In gait they may walk with their heads hyperextended to compensate for the pelvis being set posterior to the plane of the shoulders. Their hips are held in a flexed, abducted and externally rotated posture23'43'". Roentgenographically the disorder is characterized by a marked delay in the appearance of the epiphyseal ossification centers of long bones, especially the femoral heads and also a delay in ossification of the iliopubic ramus. The vertebral bodies have a biconvex appearance on the lateral - Ub view. In the lumbar area the vertebral height is greater Fig. 11 anteriorly, the pedicles are very long and the posterior Spondyloepiphyseal Dysplasia Congenita. Twenty-two year old patient with SED congenita demonstrating aplasia of the odon- elements are diminished in height. This in combination toid and atlantoaxial instability on lateral flexion and extension with the hip flexion contracture may cause the excess roentgenograms.

Volume 8 53 S. L. Weinstein

REFERENCES cal Delineation of Birth Defects, p. 207. Edited by D. 1 Alexander, Eben, Jr.: Significance of the Small Lumbar Bergsma, National Foundation - March of Dimes, New Spinal Canal: Cauda Equina Compression Syndromes Due York, 1969. to Spondylosis. Part 5: Achondroplasia. J. Neurosurg., 16- Hensinger, R.N., and Jones, E.T.: Neonatal Orthoped- 21:513-519, 1969. ics. Grune and Stratton, 1981. 2- Bailey, J.A.: Disproportionate Short Stature, Diagno- 17- Herring, J.A.: The Spinal Disorders in Diastrophic sis and Management, p. 79. Philadelphia, W.B. Saunders Dwarfism. J. Bone and Joint Surg., 60-A: 177-182, March Co., 1973. 1978. 3- Beighton, P.: Inherited Disorders of the Skeleton. 18- Hollister, David W., and Lachman, Ralph S.: Dias- Churchill Livingston, 1978. trophic Dwarfism. Clin. Orthop., 114:61, 1976. 4 Bethem, Daniel; Winter, R.B.; and Lutter, Lowell: 19 Jansen, M.: Uber atypische Chondrodystrophie Disorders of the Spine in Diastrophic Dwarfism. A Dis- (Achondroplasie) und uber eine noch nicht beschriebene cussion of Nine Patients and Review of the Literature. J. angeborene Wachstumstorung des Knockensystems: Bone and Joint Surg., 62-A: 529-536, June 1980. Metaphysare Dysostosis. Z. Orthop. Chir., 61:253, 1934. 5- Bethem, Daniel; Winter, Robert B.; Lutter, Lowell; 20- Kaufman, E.: Untersuchungen uber die sogennannten Moe, John H.; Bradford, Davis S.; Lonstein, John E.; fotale Rachitis (Chondrocystrophia foetalis). Reimer, Ber- and Langer, Leonard O.: Spinal Disorders of Dwarfism, lin, 1892. Review of the Literature and Report of Eighty Cases. J. 21- Kelly, Thaddeus E.: The Mucopolysaccharidoses and Bone and Joint Surg., 63-A: 1412-1425, December 1981. Mucolipidoses. Clin. Orthop., 114:116, 1976. 6- Bodian, M.; Sheldon, W.; and Lightwood, R.: Congen- 22- Kopits, S.E.; Perovic, M.N.; McKusick, V.A.; Robin- ital Hypoplasia of the Exocrine Pancreas. Acta Pediat., son, R.A.; and Bailey, J.A.: Congenital Atlantoaxia Dis- 53:282, 1964. loctions in Various Forms of Dwarfism. J. Bone and Joint 7- Brailsford, J.F.: Chondro-osteo-dystrophy, Roentgen- Surg., 54-A:1349, 1972. ographic and Clinical Features of Child with Dislocation 23- Kopits, S: Orthopedic Complications of Dwarfism. Clin. of Vertebrae. Am. J. Surg., 7:404, 1929. Orthop., 114:153, 1-976. 8- Burke, V.; Colebatch, J.H.; Anderson, C.M.; and 24- Kopits, S.E.: Functional Ambulation in Diastrophic Simons, M.F.: Association of Pancreatic Insufficiency and Dysplasia. SICOT Proceedings Meeting XV, Rio De Chronic Neutropenia in Childhood. Arch. Dis. Child., Janeiro, Brazil, August 30, 1981. 42:147, 1967. 25- Kozlowski, K.; Maroteaux, P.; and Spranger, J.: La 9. Cooper, R.R.; Ponseti, I.V.; and Maynard, J.A.: Pseu- Dysostose Spondylo-metaphysaire. Presse Med., 75:2769, doachondroplastic Dwarfism: A Rough Surfaced Enco- 1967. plasmic Reticulum Storage Disorder. J. Bone and Joint 26- Kozlowski, K.: Metaphyseal and Spondylometaphyseal Surg., 55-A:485, 1973. Chondrodysplasias. Clin. Orthop., 114:83, 1976. 10. Cooper, R. R., and Ponseti, I.V.: Metaphyseal Dysos- 27- Lamy, M., and Maroteaux, P.: Le nanisme diastro- tosis: Description of an Ultrastructural Defect in the Epi- phique. Presse Med., 68:693, 1961. physeal Plate Chondrocytes. J. Bone and Joint Surg., 55- 28- Lutter, L. D., and Langer, L. O.: Neurological Symp- A:485, 1973. toms in Achondroplastic Dwarfs Surgical Treatment. J. ` Dent, C.E., and Normand, I.C.S.: Metaphyseal Bone and Joint Surg., 59-A:87-92, Jan. 1977. Dysostosis, Type Schmid. Arch. Dis. Child., 39:444, 1964. 29- Maroteaux, P., and Lamy, M.: Les formes pseudo- 12- Ford, H.; Silverman, F.N.; and Kozlowski, K.: Spon- achondroplastiques de dysplasies spondyloepiphysaires. dyloepiphyseal Dysplasia (pseudo-achondroplastic type). Presse Med., 67:383, 1959. Am. J. Roentgenol. Radium Ther. Nucl. Med., 86:422, 30. Maynard, J.A.; Cooper, R.R.; and Ponseti, I.V.: Mor- 1961. quio's Disease (mucopolysaccharidosis Type IV). Ultra- 13. Giedion, A.; Prader, A.; Hadorn, B.; Shmerling, D.H.; structure of Epiphyseal Plates. Lab. Invest., 28:194- and Auricchio, S.: Metaphysare Dysostose and angebor- 205,1973. ene Pankreas-insuffizienz. Fortschr. Rontgenstr., 108:51, 31- McKusick, V.A.; Eldridge, R.; Hostetler, J.A.; Ruang- 1968. wit, U.; and Egland, J.A.: Dwarfism in the Amish. II. 14- Goldberg, M.J.: Orthopedic Aspects of Bone Dyspla- Cartilage-hair Hypoplasia. Bull. Johns Hopkins Hosp., sias. Orthop. Clin. North Am., 7:445-456, 1976. 116:285, 1965. 15- Hall, J.H., and Dorst, J. P.: Four Types of Pseudoachon- 32- McKusick, V.A.: Heritable Disorders of Connective droplastic Spondyloepiphyseal Dysplasia (SED). In Clini- Tissue. Fourth Edition. St. Louis, C.V. Mosby Co., 1872.

54 The Iowa Orthopaedic Journal Management of Deformities Secondary to Bone Dysplasia

33- Morquio, L.: Sur une forme de dystrophie osseuse 41 Spranger, J., and Wiedemann, H. R.: Dysplasia Spon- familiae. Bull. Soc. Pediat., Paris, 27:145, 1929. dyloepiphysaria Congenita. Helv. Paediatr. Acta 21:598- 34- Parrot, J.: Sur la malformation achondroplastique et le 611, 1966. Dieu Ptah. Bull. Soc. Anthrop., 1:296, 1878. 42. Spranger, J.W., and Langer L. O., Jr.: Spondyloepiphy- 35- Pedrini, v.; Lenzi, L.; and Zombotti, V.: Isolation and seal Dysplasia Congenita. Radiology, 94:313-322, 1970. Identification of Keratosulfate in Urine of Patients Affected 43- Spranger, J.W.; Langer, L. O.; and Wiedemann, H. R.: by Morquio-Ulrich Disease. Proc. Soc. Exp. Biol. Med., Bone Dysplasias. Philadelphia, W.B. Saunders Co., 1974. 110:847, 1962. 44 Spranger, J.: The Epiphyseal Dysplasias. Clin. Orthop., 36. Ponseti, I.V.: Skeletal Growth in Achondroplasia. J. 114:46, 1973. Bone and Joint Surg., 52-A: 70, 1970. 45- Stanley, P., and Sutcliffe, J.: Metaphyseal Chondropla- 37- Ponseti, I.V.: Skeletal Growth in Morquio's Disease. sia with Dwarfism, Pancreatic Insufficiency and Neutro- Scoliosis and Growth, Proceedings of the Third Sympos- penia. Pediatr. Radiol., 1:229, 2973. ium, pp. 65-81. Edinburgh, Churchill and Livingstone, 46. Stover, C.N.; Hayes, J.T.; and Holt, J.F.: Diastrophic 1971. Dwarfism. Am. J. Roentgenol., 89:914-922, 1963. 38- Rimoin, D.L.; Siggers, D.C.; Lachman, R.S.; and Sil- 47- Walker, B.A.; Scott, C.I.; Hall, J.C.; Murdoch, J.L.; berberg, R.: Metatropic Dwarfism, The Kniest Syn- and McKusick, V.A.: Diastrophic Dwarfism. Medicine, drome and the Pseudoachondroplastic Dysplasia. Chin. 51:42-59, 1972. Orthop., 114:70, 1976. 48- Zellweger, H.; Ponseti, I.V.; Pedrini, V.; Stanler, F.S.; 39- Schmid, F.: Beitrag zur Dysostosis enchondralis meta- and Von Noordeen, G.K.: Morquio-Ullrich's Disease. J. physaria. Mschr. Kinderheilk, 97:393, 1949. Pediat., 59:549, 1961. 40- Scott, C. I., Jr.: Achondroplastic and Hypochondroplas- tic Dwarfism. Clin. Orthop., 114:18, 1976.

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